Treesearch

The Fire Environmental Test Chamber at the Forest Fire Laboratory, Riverside, California, can duplicate under controlled conditions the key factors that affect the flammability of wildland fuels. Within certain limits, it can produce air flow, solar radiation, temperatures, and relative humidity. First developed in 1962, the test chamber has since then undergoneseveral modifications to meet requirements over and above the original capabilities. The characteristics of the test chamber and nature of the changes are explained. Recommendations on design and development are offered.

The volume of lumber and plywood products used in apartment construction in California was estimated from a sample of apartments for which architectural plans were completed in 1969. Excluding wood mouldings, doors, cabinets, and shelving, an average of 4.85 board feet of lumber and 2.03 square feet (318-inch basis) of plywood per square foot of floor area were used in the 17 structures studied. The ability of wood to meet fire and seismic standards at the least cost was the factor cited most often for its use. The outlook for wood in future apartment construction will probably depend...

Bands of shorthair meadow are found around lakes in the high Sierra Nevada of California. A hypothesis, based on observations in the Kings Canyon National Park, to explain the development of these meadows is offered: Boulders form the foundation upon which American-laurel, Sierra bilberry, and moss combine to produce thick mats. The lower layers of the mats are gradually converted to acid bog or mucksoil, which becomes in effect the C horizon of soil supporting the shorthair meadow type. Herbaceous plants change the upper layers and, thereby, produce an A horizon and a succession leading...

For efficient control of tree hazard on recreation sites, a specific administrative goal must be selected. A safety standard designed to achieve the selected goal and a uniform hazard-rating procedure will then promote a consistent level of safety at an acceptable cost. Safety standards can be established with the aid of data for past years, and dollar evaluations are feasible. Cost optimization is possible but impractical with available data. The legal risk in adoption of safety standards is considered acceptable.

Cutting by the minimum standard of the Rules of California's North Sierra Pine Forest District was evaluated for effects on species composition, seed fall, regeneration, and residual growth at the Challenge Experimental Forest, central California. Cutting removed 74 percent of the stand basal area and 94 percent of the merchantable volume. The heavy cut changed the species composition from primarily ponderosa pine to hardwoods and tolerant conifers. Sound seed was deficient in quantity, although trees in the cut blocks produced more seed than did trees in the control. Regeneration of...

Damage to timber surrounding clearcuttings and in one light selection cutting in mixed white fir-red fir stands was monitored for 6 years in northeastern California. In some years, bark beetles apparently killed more trees than did wind damage, but in two of the study years, severe wind storms caused much damage. One storm produced mainly break-age, apparently influenced by snow load. The other, a hurricane, produced mainly wind-throw. Relation of damage to tree size, crown class, and relative location reveals some trends. Study of height of breaks suggests that a mechanical stress point...

Traffic load changes as a result of expansion of recreation facilities may be predicted through computations based on estimates of (a) drawing power of the recreation attracttions, overnight accommodations, and in- or out-terminals; (b) probable types of travel; (c) probable routes of travel; and (d) total number of cars in the recreation system. Once the basic model has been established, development alternatives may be simulated to provide percent change estimates of probable traffic load effects on each link of the road system. Illustrative estimates are made for six alternatives for the...

The relative effectiveness of 60-second films on fire prevention, with different narrators, was tested among high school students and by exposure on commercial television channels. The narrators were Smokey Bear, a Youth, and a Ranger. All three films were effective in teaching proper fire use practices to the high school classroom audience. In commercial TV showings, fire use practices were not learned, but the Youth film was more effective than the Smokey Bear film in making the sample population interviewed more concerned about fire law enforcement.

A series of computer programs is available to extract information from the individual Fire Reports (U.S. Forest Service Form 5100-29). The programs use a statistical technique to fit a continuous distribution to a set of sampled data. The goodness-of-fit program is applicable to data other than the fire history. Data summaries illustrate analysis of fire occurrence, detection and initial attack time, and space and time relationships of multiple fires.

An initial survey in 1964 measured the existing levels of knowledge and attitudes concerning use and abuse of fire in wildland areas among residents of Butte County, California. During the next 6 years, the California Division of Forestry carried out an intensive fire prevention program. A resurvey was conducted in 1970 to find out if any changes in levels of knowledge and attitude resulted. The evaluation showed little change during the interim. The number of fires in the study area dropped during the period of most intensive prevention activity. But the analysis was not conclusive in...